Sheet material joint



May 1, 1945. J. D. GRANVILLE SHEET MATERIAL JOINT IFiled Aug. 4. 1945 \n'f////////A f Z'SEPH D. GQANV/LLE,

A Trae/ver s.

Patented May 1, 1945 UNITED STATES PATENT oFFlcE SHEET MATERIAL JOINT Joseph D. Granville, Los Angeles, Calif. Application August 4, 194.3, Serial No. 497,410

2 Claims.

This invention relates to a means and methods of joining contiguous sheets of sheet material, such as sheet metal, whereby the formation of the holes that are to receive the bolts or other fastening elements need not be accomplished with extremev accuracy.

In the construction of a large number of various fabrications of sheet metal it is frequently extremely diiiicult to locate the bolt holes of continguous sections with the required accuracy to enable the insertion of the bolt without having a loose fit. If the bolt ts the holes loosely it may loosen and what is usually a more serious objection, there is insufficient bearingy contact between the walls of the bolt holes and the bolt to form a satisfactorily sturdy structure.

Heretofore, where two superposed or contiguous elements of a fabrication are to be bolted together it has vbeen a common practice to cut disaligned slots in the pieces. These slots have been usually arranged at approximately right angles to each other. When the parts are brought to position portions of these slots are in registration and the registered portions are utilized to receive the bolt or other fastening element. The lengths of the slots provide for an adjustment and thus under these 'circumstancesy accurate lo cation of the Ibolt holes is unnecessary.

'An objection to the above-described type of joint is that the parts, when bolted together, are free to slide relatively to each other vand the bearing engagement between the sidesl of the slots and the bolt is small. y v

An .object of the present invention is to provide a joint between sections of contiguous malleable or ductile sheet material possessing all of the advantages of the adjustment of the jointl above mentioned, and in addition having a type of interlock between the sections of sheet material so that when they are bolted together they are no longer free to slide relatively to each other. By forming this interlock, stresses may be transmitted from one sheet to the other without requiring a great amount of bearing engagement between the sides of the slot and the bolt.

Another object of the invention is to provide a method of joining sections of malleable or ductile sheet material whereinit is unnecessary to accurately locate the bolt holes and an interlock is formed between the sections of sheet material so that the joint will not loosen and will adequately transmit stresses whenever required.

With the foregoing and other objects in view, which will be made apparent in the following detailed description and specically pointed out in the appended claims, reference is had to the accompanying drawing for an illustrative embodiment of the invention, wherein;

Figure 1 is a partial top plan View of two sections of sheet material illustrating the bolt eX- tending therethrough in horizontal section and illustrating these pieces as having been jointed in accordance with the present invention.' This view may be regarded as a horizontal section taken substantially upon the line I-I upon Fig. 2;

Fig. 2 is a vertical section taken substantially upon the line 2-2 upon Fig. 1 in the direction indicated;

Fig. 3 is a vertical section taken substantially upon the line 3-3 upon Fig. 2;

Fig. 4 is a bottom plan View of one of the washers or deforming elements forming a part of the joint embodying the present invention; and

Figs. 5 and 6 are edge views in elevation taken in the directions of the arrows 5 and 6, respectively of Fig. 4.

Referring to the accompanying drawing wherein similar reference characters designate similar parts throughout, l0 and Il indicate two sections of sheet material, such as sheet metal, that is to be connected togetherin contiguous relationship. If each of these sections are parts of relatively large fabrications, such as for example, the skin surfaces on airplanes it is frequently quite diicult to accurately locate the holes for the loolts so that these holes will properly register when the sections I and Il are brought together in assembled relationship. In accordancewith the present invention disaligned slots are cut in the .two sections, these slots being indicated at I2 vand I3 respectively. Preferably and in order to secure the maximum amount of adjustment the lengths of the two slots I2 and I3 are arranged at approximately right angles to each other. The widths of the slots are'equal to the diameter of the bolt I4 that is to serve as the fastening element.

In accordance with the present invention two washers or deforming elements are provided indicated at I5 and I6. These washers or deforming elements are duplicates of each other, one Fbeing positioned against the head of the bolt and the other against the nut. Y

Each washer or deforming element comprises a body Il in which there is an aperture I8 which receives the shank of the bolt. On one 'face of the body there are formed two diametrically op- I posed bosses I9 and 20 which slope from their outer ends downwardly toward the aperture I8, see Fig. 6.

The widths of these bosses are substantially p equal to-the width of slot I2. Two other bosses .2| and 22 are formed on the samey face of the body these bosses extending in directions that are circumferentially spaced approximately 90 from the bosses I9 and 20. As shown on Fig. 4, these bosses are preferably triangular in form and slope downwardly from each side of a lcentral ridge 23, the outer end of which also slopes downwardly as at 24. Notches 25 may be formed on the opposite face of the body I1 to facilitate locating the washers with relation to washer is applied against the upper side of sec-` tion IIv with its bosses I9 and 20 tting in the the nut applied and tightened. During the tightening the triangular bosses 2| and 22 on the lower washer I6 engage the sheet material II at the sides of slot I3'and beneath slot I2 and press it i upwardly as indicated somewhat exaggeratedly at 26, see Fig. 2. The inclined faces of the bosses n2,374,743 v t l It will be appreciated t t by the improved joint it is unnecessary to endeavor to accurately locate the holes in the two sections I0 and II to receive the bolt I4. The slots I2 and I3 may be cut in the sections at the approximate locations. On assembly, portions of these slots will be brought into registration and the bolt inserted through the registering portions. On tightening the bolt the two sections are interlocked together so that tendency of the bolt rto loosen is largely having other formations than that `illustrated l ends of slot |73., The boit 14 .is then inserted and 1 I9 and 2D of the upper washer form a surface against which the portions 26 may be embossed or bent. In a similar manner the triangular bosses p 2I and 22 on the upper washer I5 engage the sheet material I0 at the sides of slot I2 and press this material downwardly as at 2l, see Fig.

3. into engagement with the bosses I9 and 20 of the lower washer. This downwardly bent or em- 1 i bossed portion of section. I0 enters the space 4. 3 within slot I3. In this manner both sections of sheet material are bentflaterally at the sides of their respective slots. They are bent into the slots of the adjacent piece, thus forming a type of interlock which when the bolt is tightened, locks the sections I0 and II against sliding relatively' to each other. only tends to maintain the joint tight, but will Thistype of interlock not serve to leectively transmit stresses from section I0 to section II without the edges of the slot being in any .great bearing engagement with the sides of the shank of the bolt. It is not necessary that the sides of the slots be deformed tothe extent illustrated. Only a slight deformation of the sections I0 and I I adjacent the slots is neces- 'sary in order to secure the advantages of the improved joint.

might be employed, the only essential requirement being that these washers present surfaces which, on tightening the bolt, will depress the material of one sheet adjacent the sides of those slots into the space afforded by the slot ofthe other sheet. f

The invention, of course, is only applicable to sections of material that are malleable or deform-A able to some degree, it being inapplicable to unyielding, brittle materials such as castV iron and the like, `unless the section that is to be attached thereto is malleable and deformable so as to be capable of having a portion adjacent its slot depressed into the slot in the cast iron.

Various changes may be made 1n the details of construction without departing from the spirit and scope` of the invention as defined bythe appended claims. f

Iclaim:

1. A joint between contiguously arranged sheets of material comprising disaligned but partially registering slots in both sheets, a fastener extending therethrough, washers on the fastener against the sheets, eachv washer having bosses fitting between the sides of the Slot in its respec.- tive sheet, and other bosses depressing the material of its sheet adjacent the sides of its 'slot into the slot of the other sheet. I

2. A joint between contiguously arranged sheets of material comprising disaligned but partially registering slots in both sheets, ta fastener extending through the registering portions of the slots andv washersv on the fasteners disposed against the sheets, each washer having bosses 

